9 7 Laws of Sines and Cosines Geometry
- Slides: 10
9. 7 Laws of Sines and Cosines. Geometry EQ: How do you find the area of any triangle using Sine?
Goals n n Know Laws of Sines and Cosines to solve triangles Find the areas of triangles 21 January 2022 Geometry 9. 3 Similar Right Triangles 2
Area of a triangle. The area of any triangle is given by on-half the product of the lengths of any two sides times the sine of their included angle. B c A 21 January 2022 Geometry 9. 3 Similar Right Triangles a b C 3
EX: Find the area of the triangle A =. 5(6)(14)sin 95 A = 42 sin 95 6 in 95⁰ 14 in A = 42(. 9962) 21 January 2022 Geometry 9. 3 Similar Right Triangles 4
Laws of Sines: Not just for right triangles anymore. You can use Law of Sines to solve any triangle when two angles and any length are known. Theorem 9. 9: The Law of Sines can be written in the form 21 January 2022 Geometry 9. 3 Similar Right Triangles 5
EX: Solve the Triangle. First find Angle B 21 January 2022 Geometry 9. 3 Similar Right Triangles 6
Continued: 21 January 2022 Now find length c Geometry 9. 3 Similar Right Triangles 7
Law of Cosines Use Law of Cosines when two sides and an included angle are known. Theorem 9. 10 Law of Cosines 21 January 2022 Geometry 9. 3 Similar Right Triangles 8
EX: Solve the triangle 21 January 2022 Geometry 9. 3 Similar Right Triangles 9
Continued Use Laws of Sines to find A or C 7. 9 21 January 2022 Geometry 9. 3 Similar Right Triangles 10
